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Message-ID: <BECD8E8A1B550B48A1BF97C13991F60E32079A@avmb2.qlogic.org>
Date: Mon, 13 May 2013 15:42:21 +0000
From: Jitendra Kalsaria <jitendra.kalsaria@...gic.com>
To: Thadeu Lima de Souza Cascardo <cascardo@...ux.vnet.ibm.com>,
netdev <netdev@...r.kernel.org>
CC: Dept-Eng Linux Driver <Linux-Driver@...gic.com>,
Shahed Shaikh <shahed.shaikh@...gic.com>,
Ron Mercer <ron.mercer@...gic.com>
Subject: Re: [PATCH] qlge: fix dma map leak when the last chunk is not
allocated
On 5/11/13 12:15 PM, "Thadeu Lima de Souza Cascardo"
<cascardo@...ux.vnet.ibm.com> wrote:
>qlge allocates chunks from a page that it maps and unmaps that page when
>the last chunk is released. When the driver is unloaded or the card is
>removed, all chunks are released and the page is unmapped for the last
>chunk.
>
>However, when the last chunk of a page is not allocated and the device
>is removed, that page is not unmapped. In fact, its last reference is
>not put and there's also a page leak. This bug prevents a device from
>being properly hotplugged.
>
>When the DMA API debug option is enabled, the following messages show
>the pending DMA allocation after we remove the driver.
>
>This patch fixes the bug by unmapping and putting the page from the ring
>if its last chunk has not been allocated.
>
>pci 0005:98:00.0: DMA-API: device driver has pending DMA allocations
>while released from device [count=1]
>One of leaked entries details: [device address=0x0000000060a80000]
>[size=65536 bytes] [mapped with DMA_FROM_DEVICE] [mapped as page]
>------------[ cut here ]------------
>WARNING: at lib/dma-debug.c:746
>Modules linked in: qlge(-) rpadlpar_io rpaphp pci_hotplug fuse [last
>unloaded: qlge]
>NIP: c0000000003fc3ec LR: c0000000003fc3e8 CTR: c00000000054de60
>REGS: c0000003ee9c74e0 TRAP: 0700 Tainted: G O (3.7.2)
>MSR: 8000000000029032 <SF,EE,ME,IR,DR,RI> CR: 28002424 XER: 00000001
>SOFTE: 1
>CFAR: c0000000007a39c8
>TASK = c0000003ee8d5c90[8406] 'rmmod' THREAD: c0000003ee9c4000 CPU: 31
>GPR00: c0000000003fc3e8 c0000003ee9c7760 c000000000c789f8 00000000000000ee
>GPR04: 0000000000000000 00000000000000ef 0000000000004000 0000000000010000
>GPR08: 00000000000000be c000000000b22088 c000000000c4c218 00000000007c0000
>GPR12: 0000000028002422 c00000000ff26c80 0000000000000000 000001001b0f1b40
>GPR16: 00000000100cb9d8 0000000010093088 c000000000cdf910 0000000000000001
>GPR20: 0000000000000000 c000000000dbfc00 0000000000000000 c000000000dbfb80
>GPR24: c0000003fafc9d80 0000000000000001 000000000001ff80 c0000003f38f7888
>GPR28: c000000000ddfc00 0000000000000400 c000000000bd7790 c000000000ddfb80
>NIP [c0000000003fc3ec] .dma_debug_device_change+0x22c/0x2b0
>LR [c0000000003fc3e8] .dma_debug_device_change+0x228/0x2b0
>Call Trace:
>[c0000003ee9c7760] [c0000000003fc3e8]
>.dma_debug_device_change+0x228/0x2b0 (unreliable)
>[c0000003ee9c7840] [c00000000079a098] .notifier_call_chain+0x78/0xf0
>[c0000003ee9c78e0] [c0000000000acc20]
>.__blocking_notifier_call_chain+0x70/0xb0
>[c0000003ee9c7990] [c0000000004a9580] .__device_release_driver+0x100/0x140
>[c0000003ee9c7a20] [c0000000004a9708] .driver_detach+0x148/0x150
>[c0000003ee9c7ac0] [c0000000004a8144] .bus_remove_driver+0xc4/0x150
>[c0000003ee9c7b60] [c0000000004aa58c] .driver_unregister+0x8c/0xe0
>[c0000003ee9c7bf0] [c0000000004090b4] .pci_unregister_driver+0x34/0xf0
>[c0000003ee9c7ca0] [d000000002231194] .qlge_exit+0x1c/0x34 [qlge]
>[c0000003ee9c7d20] [c0000000000e36d8] .SyS_delete_module+0x1e8/0x290
>[c0000003ee9c7e30] [c0000000000098d4] syscall_exit+0x0/0x94
>Instruction dump:
>7f26cb78 e818003a e87e81a0 e8f80028 e9180030 796b1f24 78001f24 7d6a5a14
>7d2a002a e94b0020 483a7595 60000000 <0fe00000> 2fb80000 40de0048 80120050
>---[ end trace 4294f9abdb01031d ]---
>Mapped at:
>[<d000000002222f54>] .ql_update_lbq+0x384/0x580 [qlge]
>[<d000000002227bd0>] .ql_clean_inbound_rx_ring+0x300/0xc60 [qlge]
>[<d0000000022288cc>] .ql_napi_poll_msix+0x39c/0x5a0 [qlge]
>[<c0000000006b3c50>] .net_rx_action+0x170/0x300
>[<c000000000081840>] .__do_softirq+0x170/0x300
>
>Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@...ux.vnet.ibm.com>
>---
Looks good to me. Thanks!
Acked-by: Jitendra Kalsaria <Jitendra.kalsaria@...gic.com>
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